MISO Winter PRA Surplus Shrinks as Wind, Coal and Gas Accreditation Cut — Cold-Shot Risk Skews ZRC Tightness Bullish for Henry Hub Burn

MISO Winter PRA Surplus Shrinks as Wind, Coal and Gas Accreditation Cut — Cold-Shot Risk Skews ZRC Tightness Bullish for Henry Hub Burn MISO's 2025-26 Winter Planning Resource Auction cleared with a smaller surplus of Zonal Resource Credits than the prior winter, and the reason is structural: an updated LOLE model pushed winter risk into the hours when wind is least effective, cutting winter wind accreditation, while coal and gas accreditation fell on historical performance. Cleared capacity sits at roughly 102.6 GW across December, January and February against a 50/50 coincident peak forecast near 102.6-102.7 GW and a 90/10 non-coincident peak of 123.1 GW. The thinner cushion against a weak-La Niña winter that MISO itself flags as cold-shot-prone is the read: bullish for NYMEX Henry Hub winter str4ength and for MISO real-time scarcity pricing on the cold days, not a base-case shortfall. The weather frame is the swing factor. MISO names winter 2024-25 — seven days at or below 10°F systemwide, temperatures nearly as cold as 2017-18 — as the top analog. NOAA calls equal chances for North and Central, above-normal for the South. But the desk-relevant tail is MISO's own statistic: historical weak-La Niña years drive systemwide peak load to a 95th-percentile near 97 GW, and weaker stratospheric winds raise polar-vortex disruption odds. Against ~102.6 GW cleared, a 97 GW load print under a sustained cold outbreak leaves margin, but the accreditation haircut means the marginal cold hour now leans harder on gas-fired generation that clears at the top of the stack. The renewable risk is quantified and large. MISO puts potential wind power loss at 24.4 GW when temperatures fall to -30°F or below — a number that lands precisely in the hours the new LOLE model identified as highest-risk. Analog winters point to normal-to-above-normal wind generation on average, but the average is not the trade; the -30°F tail is. Above-normal precipitation across the Great Lakes raises icing and snowfall, degrading wind forecast accuracy in North/Central exactly when load peaks. Each GW of wind that fails to show forces gas burn or emergency imports, steepening intraday MISO LMPs and pulling on regional cash gas (Chicago Citygate, Henry Hub) on the coldest mornings. Transmission is not the binding constraint. The Coordinated Seasonal Assessment studied 18,500+ P1 contingencies and found none without an operating plan; MISO calls itself well positioned for unplanned winter events. Load-pocket import limits hold at current operating guides — Amite South 3,222 MW, DSG 2,268 MW, SETEX ~2,625 MW (the SETEX case failed to converge, requiring added generation or reactive support, the one flagged soft spot). East-West transfer capability across the footprint into PJM/SERC and SPP/AECI remains deep, with leading constraints identified above realistic 15,000 MW transfer levels. The risk is generation availability in cold, not wires. Net: this is a tightening-at-the-margin winter, not a capacity crisis. The PRA surplus erosion plus the wind/thermal accreditation cuts mean the system has less headroom precisely in the cold-correlated, low-wind hours — the setup that rewards length in winter Henry Hub and prompt MISO power on a confirmed arctic intrusion, and that makes the spread between mild and cold scenarios wider than last winter's. What to Watch - Polar-vortex / stratospheric-warming signals through Dec-Feb — the weak-La Niña cold-shot trigger MISO flags as higher-probability - Realized wind output on sub-zero mornings vs the 24.4 GW loss-at-(-30°F) threshold; icing events across North/Central - Cold days where load approaches the 97 GW weak-La Niña 95th-percentile against ~102.6 GW cleared — scarcity-pricing risk in MISO real-time - Henry Hub and Chicago Citygate cash on confirmed arctic intrusions; SETEX load-pocket support given the non-converged contingency case